There's still plenty of room to innovate in the fantasy genre. Just look at the variety of "D&D" settings throughout the years - Greyhawk, Forgotten Realms, Mystara, Dragonlance, Eberron, Golarion (Pathfinder), etc. They all have their own unique flavor but still fall under the medieval fantasy umbrella. As long as it's not yet another Tolkienesque re-hash I'll be happy.